Regulation of carotenoid formation during tomato fruit ripening and development.

Carotenoid biosynthesis and its regulation during tomato fruit development and ripening is a complex process that occurs alongside the differentiation of chloroplasts into chromoplasts and changes to the organoleptic properties of the fruit. Unusually for plants, the ripe tomato fruit accumulates large amounts of lycopene, as the pattern of gene expression found in green fruit changes during fruit ripening. Although the control of gene expression is thought to be the main regulatory mechanism for these alterations in carotenoids, post-transcriptional regulation has also been reported, including feedback inhibition. The use of genetic manipulation of carotenogenesis in tomato has been used primarily for biotechnological reasons, but it has also facilitated investigations into these regulatory mechanisms, as well as into the effects of such perturbations on other isoprenoids such as gibberellins, tocopherols and sterols.